Blowing device for rock drills



Nov. 10, 1931. A. G. SLATCHER 3 BLOWING DEVICE FOR ROCK DRILLS Filed May 31. 1927 3 e, I Q I Wig/ ya I 24 w Q5 2 w W i 3 59 lb. Z7

25 \m 4 w 1/ 25 v L6e Patented Nov. 10, 1931 UNITED STATES AT NT oFF ce ALFRED G. SLATGI-IER, or CLEVELAND, 01:10, AssIenoR TO THE CLEVELAND noon 7 DRILL COMPANY, oroLnvELAnn, onto I a I 1 BLOWING DEVICE FOR ROCK DRILLS Application filed May 31,

The present invention is directed to improvements in blowing device forv rock drills.

The primary object of the invention is to provide means whereby the piston hammer will be held immovably in its rearward position in order that an uninterrupted supply of air under line pressure will be directed into the hole being drilled to blow the cuttings therefrom.

Another object of the invention is to provide a pin capable of being moved to a position to maintain the piston hammer controlling valve in such position that air under line pressure will pass therearound, through the drill cylinder, and from thence through the cleansing hole of the drill steel as long as the pin is held in its operative position.

In the accompanying drawings c Figure 1 is a longitudinal sectional view, showing the valve in its position to permit air to blow through the drill steel.

Figure 2 is a face view of the disk.

Referring to the drawings, 1 designates the drill cylinder having mounted therein for reciprocation the piston hammer 2 provided with the conventional fluted extension 3.

The cylinder is provided with a chest 4: in the ends of which are fitted plugs 5 and 6, the former having a socket 7 formed therein. A rod 8 is employed and slidable thereon is a valve 9, said rod having a head 10 adapted to bear against the cap 6, there being a coil spring 11 engaged upon the outer end of said rod and occupying the socket 7 of the cap 5. A nut 11 is threaded on said rod for engagement with the spring and serves to maintain the rod in place.

The chest is formed with a live air port 12 which opens into the bore 13 in which the valve 9 is movable. Live air passages 14 and 15 lead from the bore 13 to the front and rear ends of the hammer chamber 16 to efiect the reciprocation of-the piston hammer during reciprocation of the valve 9. Crossed passages 17 and 18 afford fluid communication between the piston chamber 16 and bore 13 of the valve chest, passage of motive fluid through said passages being controlled by the piston hammer 2 to alternately admit motive fluid against the ends of the valve 9 to effect 192?. serial No.195,351.

the shifting thereof. Exhaust ports 19 and 20 lead to atmosphere upon opposite sides of the liveair port 12. V p f f The valve 9 is .of the. spool type and comprises a pairof centrally disposed webs i21-121and spaced terminal webs 22-22 and 2323, the webs 21-21 controlling The head 10 of the rod 8 is provided with a i reduced hub 24 which in turn is formed with a threaded extension 25, and rotatably engaged on the hub is a disk 26, said disk having its inner face formedwitha recess 27, the purpose of which will appear later.

Formed in the cap 6 is a bore 28 and slidable therein is a pin 29, the inner end of which is capable of being projected a short distance into the adjacent end of the bore13. The outer end of the pin is formed with ahead 30 and encircling said pin is a coil spring 31, one

end of which rests against the cap 6 While the other end thereof engages the head 30 and normally serves to hold the pin in its inoperative position. The disk 26 is retained upon (the hub by a nut threaded upon theextension As shown in Figure 1 of the drawings the pin 29 has'itsinner end projected into the bore 13 and is in contact with the adjacent end of the valve 9, thusholding the same in its rearward position in order that live air can pass therearound and will flow through the passage 15 into the hammer chamber 16,-

and from thence through the flutes of the hammer extension 3 into the bore of the drill steel 32 in order to blow the cuttings from the hole being drilled. After the drill hole has been thoroughly blown or cleansed, the disk is rotated until the head 30 of the pin rides into the recess 27, whereupon the spring 31, which had previously been compressed will expand and force the pin outwardly,

thereby permitting the valve to shift for wardly in order that live air will be permitted to pass into the passage 14 to drive the piston forwardly, the reciprocation of the valve and piston hammer being maintained until it is again desired to cleanse the hole being drilled.

It will be of course understood that as long as live air is flowing into the chamber 16 the hammer 2 will be held inits rearward position owing to the pressure being built up therein which is not entirely relieved as the motive fluid flows by the hammer ex tension 3. The recess 27 performs the same function as a cam in conjunction with the flat surface upon opposite sides thereof. Therefore, as long as the head 30 ofthe pin engages the flat surfaces of the disk the inner end thereof will be projected into .the bore of the valve chest, the spring 31 obvious- 1y forcing the pin outwardly in order to positively force said head into the recess after the blowing of the hole has been effected.

WVhat is claimed is In a fluid actuated rock drill of the hammer type, the combination of a cylinder, a

hammer piston therein having a fluted extension thereon, a valve chest having a chamber, supply passages leading from the chamber to the ends of the cylinder, a rod axially disposed within said chamber, a valve in said chamber reciprocatively mounted upon said rod, a pin slidably mounted in said valve chest and disposed in a plane parallel with the said rod, the pin being adapted for reentrant engagement with said valve, a spring normally holding the pin out of contact with the valve, means for actuating the pin to arrest the reciprocati've movement of the valve and hold said valve to effect the flow of fluid from a source of supply through said chamber and the passages to the end of the cylinder to the fluted extension of said hammer piston, said means comprising a disc rotatably mounted upon said rod and having the inner face thereof disposed to engage the pin and efiect its engagement with the valve and a recess in the inner face of said disc to receivethe outer end of the normal operation of the drill.

In testimony whereof I aiiix my signature.

ALFRED G. SLATGHER- pin during the V 

